Polymers have been grafted onto non-metallic substrate surfaces, such as cellophane, for example, as described in U.S. Pat. No. 3,401,049. The basic process of grafting of the polymer comprises the contacting of the non-metallic body, for example, with a solution of silver nitrate and an alkali metal hydroxide, then contacting the thus treated body with a polymerizable composition of a polymerizable monomer and a catalyst, the polymerization taking place directly on the molecules of the substrate. As described in U.S. Pat. No. 3,401,049, the polymerization can take place at room temperature, in which case, considerable time is required, or it can be accelerated by heat.
In more recent processing, the grafting of the polymer onto the substrate has utilized radiation, corona discharge, UV treatment and thermal treatment to accelerate the polymerization and cure the polymer. The processing is in general the same, namely the activated surface of the substrate is brought into contact with a grafting solution which contains the monomers, prepolymers, catalyst and graft initiator system, and the resulting graft treated surface is then subjected to cure as set forth above.
However, all of the methods are either too hazardous, such as grafting by means of radiation, or too time and energy consuming, such as grafting by UV or thermal treatment.
The need has arisen for a more rapid yet safe method of grafting of polymers onto substrates.